From 9b0b9ac237c60d34c9cd06538d1a133eed9f7130 Mon Sep 17 00:00:00 2001
From: mrkn <mrkn@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Wed, 11 Aug 2010 14:30:47 +0000
Subject: [PATCH] * lib/cmath.rb (CMath.sqrt): use floating-point value. 
 [ruby-core:31672] [Bug #3678] * test/test_cmath.rb: added for testing
 lib/cmath.rb.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@28964 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 ChangeLog          | 7 +++++++
 lib/cmath.rb       | 2 +-
 test/test_cmath.rb | 8 ++++++++
 3 files changed, 16 insertions(+), 1 deletion(-)
 create mode 100644 test/test_cmath.rb

diff --git a/ChangeLog b/ChangeLog
index a4d5ea1cdc..2465e5d387 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Wed Aug 11 23:28:22 2010  Kenta Murata  <mrkn@mrkn.jp>
+
+	* lib/cmath.rb (CMath.sqrt): use floating-point value.
+	[ruby-core:31672] [Bug #3678]
+
+	* test/test_cmath.rb: added for testing lib/cmath.rb.
+
 Wed Aug 11 20:57:25 2010  Kazuhiro NISHIYAMA  <zn@mbf.nifty.com>
 
 	* NEWS: merge from branches/ruby_1_9_2, and move io/console.
diff --git a/lib/cmath.rb b/lib/cmath.rb
index 976f269299..3c94221f2c 100644
--- a/lib/cmath.rb
+++ b/lib/cmath.rb
@@ -79,7 +79,7 @@ module CMath
       else
 	r = z.abs
 	x = z.real
-	Complex(sqrt!((r + x) / 2), sqrt!((r - x) / 2))
+	Complex(sqrt!((r + x) / 2.0), sqrt!((r - x) / 2.0))
       end
     end
   end
diff --git a/test/test_cmath.rb b/test/test_cmath.rb
new file mode 100644
index 0000000000..46a357fab2
--- /dev/null
+++ b/test/test_cmath.rb
@@ -0,0 +1,8 @@
+require 'test/unit'
+require 'cmath'
+
+class TestCMath < Test::Unit::TestCase
+  def test_sqrt
+    assert_equal CMath.sqrt(1.0.i), CMath.sqrt(1.i), '[ruby-core:31672]'
+  end
+end